(CNN) -- One man died and another was critically injured Saturday evening after they were shot at a shopping center in Tukwila, Washington.

The men who were shot were taken from the Westfield Southcenter on stretchers and placed in ambulances.

Authorities were still searching for the shooter, a police spokesman Mike Murphy said.

A woman who appeared to go into labor and a man who suffered a neck injury as people rushed from the center were also taken to the hospital, Murphy said.

The shooting victims, believed to be in their 20s, were removed from the Westfield Southcenter on stretchers and taken to Harborview Medical Center, Murphy said. He didn't know how many times they were shot.

Eyewitness Chris Plummer told CNN affiliate KIRO-TV there was a fight between a group of 18- to 20-year-olds and one of them pulled out a gun and started shooting. Plummer told KIRO-TV he was standing next to the shooter when bullets started to fly, six to seven shots in all.

Murphy told KIRO-TV authorities are trying to determine whether the shooting was gang-related.

The mall was placed on lockdown as SWAT teams searched store-to-store for the shooter. At least two people were detained for questioning, but neither was the shooter, Murphy said.

Shoppers and employees described a chaotic scene.

"We were coming up from the stairs over there, and then we just heard gunshots -- maybe two or three ... then other people started running, and we started running, too," a shopper said. "It was just kind of crazy."